The sums ∑(l, m) ∈ N2, l + 6 m = n σ (l) σ (m) and ∑(l, m) ∈ N2, 2 l + 3 m = n σ (l) σ (m) are evaluated for all n ∈ N, and their evaluations used to determine the number of representations of a positive integer n by the form{Mathematical expression}.

Convolution sums, Divisor sums, Eisenstein series
Journal of Number Theory
School of Mathematics and Statistics

Alaca, S, & Williams, K.S. (2007). Evaluation of the convolution sums ∑l + 6 m = n σ (l) σ (m) and ∑2 l + 3 m = n σ (l) σ (m). Journal of Number Theory, 124(2), 491–510. doi:10.1016/j.jnt.2006.10.004